Reading aid for the blind



Aug. 1950 L. E. FLORY READING AID FOR THE BLI'ND 4 Sheets-Sheet 1 Filed NOV. 29, 1946' 0 v u M m a. V I. a F D M w F u. P M A le uizk E. Z7027 C9) (Ittorueg 1950 L. E. FLORY I 2,517,102

' READING AID FOR THE BLIND Filed Nov. 29, 1946 4 Sheets-Sheet 5 a ttorue g Patented Aug. 1 1950 READING AID Fon THE BLIND Leslie E. Flory, Princeton, N. .L, assignor to Radio Corporation of America, a corporation of Delaware Application November 29, 1946, Serial No. 713,175

The present invention contemplates artificially l reproducing speech by first recording, by any conventional means, the basic tones or sounds which comprise the spoken language, and then selecting and combining the sound components in acontrolled time sequence to reproduce artificially intelligible words. Further, the selection and sequence of the basic sound components is to be accomplished by a control or programming device containing coded indicia which can be prepared by hand or by a simple printing or punching machine. It is thus possible to write a message to a blind person, which message will then be reproduced audibly by the device. It is therefore the primary object of this invention to convert coded manually formed indicia into corresponding intelligible sound, itbeing understood that the term manually formed indicia? includes printed, stamped or perforated indicia of all types in contradistinction to recordingswhich in themselves contain the form of the sound waves, examples of the latter being the conventional recording on wax discs or cylinders, sound recording on films or magnetictape recording.

All the Words of a given language are formed by different sequences of one or more basic sound components. While there are, undoubtedly, a very large number of basic tones or sounds in normal speech with all its degrees of inflection and accent, linguists agree that intelligible speech can be reproduced by the proper combination of only different basic sounds. While this invention is not limited to this figure, purely for the purpose of illustration it will be assumed that the generation of 35 unique sounds will be sufiicient. If the acquired skill of the user makes possible intelligible communication with fewer basic sound components, or if a greater number of basic components are desired for greater fidelity, the necessary modification of the apparatus will be apparent to one skilled in the art.

1" In brief, the above objects are achieved by recording the 35 basic sounds, selecting them in a sequence determined by a simple programming device, and combining the selected sounds to form intelligible speech. Further, it is also contem- 14 Claims. ((31.179-4) plated that complete words may be recorded, an the programming device used to form sentences directly. Of course, the latter system has its primary application to annunciator systems where a very limited vocabulary is employed. 1 Consequently the sound-representing components of speech which are recorded may comprise complete words orthe unique sound components of which words are formed.

i It is a further object of this invention to provide an improved programming system for controlling by coded indicia thesequential application of a plurality of sources of energy to. a utilization device. i

A still further object of this invention is toprovide a programming device in which a relatively few distinctive inidlcia uniquely control a larger number of operable elements.

The novel features that are considered characteristic of this invention are setforth with par-- ticularity in the appended claims. The invention,

both as to its organization andmethod of oper-- ation, as well as additional objects and advantages thereof, will best be understood from the follow ing description when read in connection with the accompanying drawings, in which Fig. l is a view partly in cross-section of a portion of this invention;

Fig. 2 is a view illustrating the method of controlling the operation of the tone wheels;

Fig. 3 is a circuit diagram illustrating the method of connecting the phototubes illustrated in Fig. 1;

Fig. 4 is a circuit diagram of a portion of the programming circuit;

Fig. 5 is a view of the programming tape showing the coded indicia;

Fig. 6 is a circuit diagram of a rectifier utilized this invention in which continuously rotating tone wheels are employed;

Fig. 9 illustrates theuse of aspecial cathode ray tube to produce the speech components in lieu of the rotating tone wheels, together with the control circuit therefor;

Fig, 10 is an enlarged view of a portion of the target of the cathode ray tube illustrated in Fig. 9; r

Fig. 11 is the circuit diagram or a slide-back trigger circuit in accordance with the prior art;

with the portion illustrated in Fig. 12 illustrates a modified cathode ray tube with individual grid selector elements for controlling the vertical displacement of the beam in generating the different speech component signals; and

Fig. 13 illustrates a method of controlling the application of biasing potentials to the selector grid of the device illustrated in Fig. 12,

Similar reference numerals apply to similar parts throughout the several figures of the drawmgs.

A plurality of separate sound generators of any suitable type are provided for producing respectively distinctive oscillatory vibrations corresponding to the sound-representing components of speech. In Figs. 1 and 2 for example, 35 tone wheels I are employed, although for simplicity only three have been illustrated. Since all units are identical except for the nature of the SOLlIld recorded on each, it will only be necessary to describe one of them. The tone wheel I is rotatably mounted on a shaft 3 driven at a constant speed by a motor 5. Each tone wheel i is normally prevented from rotating by a pin 1 which is moved from engagement with the wheel by a tripping relay 9 of which it is a part. When current is applied to the coil I l of relay 9 the pi is momentarily raised, permitting the disc i to rotate once in response to the torque applied by a friction clutch plate l3 which is held against the disc and rotated by a spring [5, one end of which is firmly anchored on the shaft 3. A thrust bearing 51 is provided for each disk to hold it in position.

One of the 35 distinctive sounds is recorded photographically near the circumference of the disc I, as shown at is in Fig. 2. The sound may be reproduced by means of a light source 2| and a phototube 23 associated with each disc. The phototubes 23 are connected as shown in Fig. 3 although, for simplicity, only 3 of the 35 tubes have been illustrated. The tubes are all connected in parallel, a bias cell 25 being connected between anode and ground and output being developed across an output resistor 21 connected between cathode and ground. An amplifier 29 applies the audio signal to a loudspeaker or headset 3|.

The control or programming system for operating the tripping relays in a desired predetermined sequential order will now be described.

Referring to Figs. 4 and 5, the image 33 of a slit of light is projecting by a suitable source 35 on a paper tape 31. The paper tape is moved in a direction perpendicular to the slit at a constant reflected from or transmitted through the paper at any instant at the region then lying under respective halves of the image 33.

It will be observed that, including zero, there are six indicia lengths or six degrees of light intensity which will produce corresponding current intensities in each phototube. Considering all possible variations of indicia, there are 36 unique combinations which can be made by combining one indicium of the first series with one of the second series. Eliminating the "zerozero combination, since it is the same as a space, there result unique coded combinations available for use. Thus the 35 unique combinations of an indicium of the first series with an indicium of the second series will be used to operate the 35 sound generators. It should be noted that with only it variations in the form of the indicia, approximately 112 generators can be controlled independently. Also it should be noted that the tape can readily be printed or punched by hand, or by a simple perforating or printing machine, with only 5 different characters or shapes (not counting zero), and yet 35 tones can be controlled from which intelligible speech can be produced. A few typical combinations are shown on the right hand portion of the tape 31 in Fig. 5.

Referring again to Fig. 4, the output of phototube 43 is amplified by an amplifier 45 and applied to the control grid of a reactance tube 61 which is connected across the tank circuit of an oscillator 49 in conventional manner. The phototube 4| is identically connected to another amplifier, reactance tube and oscillator, shown as a block diagram St for simplicity.

The output of oscillator 49 is coupled to the parallel-connected grids of six coupling tubes 53a, 55a. 51a, 5951., (Na, and 63a. The output circuits of these tubes includes six band pass filters, 55a, 81a, 69a, lla, 13a, and a, respectively. The six band pass filters are connected to six rectifiers, 11a, 19a, 81a, 83a, 85a and 81a, respectively. The output of each rectifier is available between ground and six output terminals of group a 89a, Qla, 93a, 95a, 91a, and 09a. The output of the second amplifier-oscillator 5i is connected in an identical manner to six coupling tubes, band pass filters and rectifiers to six output terminals of group b. For purposes of identification similar reference numerals of the two groups have corresponding subscripts.

The operation of the device so far described is as follows: The output of phototube 43 varies through six discrete steps as the indicia of the first series pas under the light image. The current variations control the grid voltageof the reactance tube 41 through a range of values which cause the oscillator frequency to vary in like steps between two predetermined values which may be, for example, from 1000 to 1250 k. c. The six band pass filters of each group are eachtuned to pass one frequency in this range, preferably in 50 k. 0. steps, i. e., 1000, 1050, 1100, 1150, 1200 and 1250 k. 0. respectively. Consequently for each indicium of the first series a D. C. Voltage will appear at one and only one of the a group output terminals 89a, am 99a, while asimilar voltage will appear at one of the h group of terminals as determined by the indicium of the second series scanned concurrently. Thus there will be 35 unique combinations of voltages, excluding the case in which both indicia are zero.

The circuit of each rectifier is shown in Fig. 6. Input is applied between ground and the anode of a diode in l, the cathode being connected capacitor is completely discharged before the next successive controlsignal arrives.

The circuit for combining the two control signals to operate one relay for each unique combination is illustrated in Fig. 7 in which the twelve output terminals of Fig. 4 are shown. A resistance matrix I09 is utilized which comprises amma twelve, vertical and 35 horizontal conductors interconnected by resistors in auman'ner to be described. It is to be understood, ofcourse, that the orthogonal arrangement of theconductors is purely for convenience ofillustration, the only operational requirement being that the circuits are connected as shown.

The twelve vertical conductors are connected, respectively, to the twelve input terminals sea to 99a and 89b to 9921. The 35 horizontal conductors are connected. to the grid electrodes of 35 amplifier tubes" II I, respectively, The cathode electrodes of all amplifier tubes are connected together and to ground through a bias battery I13 which provides a positive cathode] bias. Each horizontal conductor is connected by a resistortofrelatively high value, say 500,0Q0ohnis, to onevertical conductor of each group. However, no two horizontal conuductors are connected to the same two vertical conductors. Also, since the combination zero-zero ishot used, there is no tube whose grid is connected to both terminals 89a andBBb. One of the 35, tripping relays I9 is connected in the plate circuit of each tube I I I, in this instance all 35 tubes and relays being shown. It is understood that the solenoid I I of each relay 9 is serially connected between the respective plate electrodes and a common source of plate potential available at terminals IISandIII.

It willbe observed that the grid of each tube III is connected to the midpoint of two resistors which terminate at one terminal of the a group and one terminal of the 1) group. For example, the grid of tube I I9 is connected to the midpoint of resistors I2I and I23, which connect to terminals 89a and SH), respectively.

Assuming that the corresponding indicia on tape 31 have caused positive potentials to appear on these terminals, thegrid of-tube I I9 will have thesame value, say +1.5 volts, for example. The value of the bias voltage produced by battery II3 has a value of, say, 1 volt and the tube conducts, causing the associatedrelay 9 to operate, and the first tone disc I rotates once. If, however, there is a positive potential on only one of the two terminals, the other being essentially grounded through resistor Illl of the rectifier, which preferably has a low value as compared to the matrix resistors, then the grid voltage will beonly +.75 volt, which is insufiicient to overcome the 1 volt bias, and thetube remains cut ofi. Thus it can be seen that for each unique combination of indicia one and only one relay will operate, thus controlling the operation of the tone discs in the sequence determined by the coded indicia on the tape.

An alternative embodiment of this invention is illustrated in Fig. 8. The programming arrangement illustrated in Fig. ,4 is employed, as

before. Also, as before, the twelve terminals or groups a and b are connected to an identical resistance matrix I09, as in Fig. 7, the horizontal conductors of which connect to the grid electrodes of 35 tubes III, only 3 of which are now illustrated, since all the others are identical. However, the tripping relays 9 and the mechanical starting system for the tone wheels I are replaced by a wholly electronic control. Thus, in Fig. 8, the 35 tone wheelsI are now fixedly mounted on shafts and all are rotated con: tinuously. A before, each recorded soundtrack is scanned by a phototube 23, the output of each phototube being coupled to the gridof one of the eei ifi mubes, it, :I-h .rletaea e es?al a tubes I I are, connected, together; a.1,1cl, throughan output resistor I25, to the-source 1? plate, po-.' tential atterminal'fI I5. A iitiliz'ati ,devipe lfll is ,coupledto the, output resistor to, convent the, modulated electrical fcurrents, a11 audi sound. of suitable amplitude. before, hecathode electrodes of tubes III are co ected totground through a biasingbattery .I,I3,. l

In operation, one tube] III at; a timebecomes operative and passes a modulatedaudio. ne to, the utilization device, the sequencefbeing de termined by'the indicia on. the tape ;,of the programming device. 1, All other. tubes are, biased pitand pass no audio signal to the output {The time interval during which the conducting tube, remains operative should, be equalto the billll} required for the tone wheel to; make. one] revolue tion. 'Thismay be accomplished by adjustment of the time constant of the rectifier resistors, I03 and I01 with respect to capacitor, I05, or,f alter natively,. if output potential from; resistorq lllflqjs taken directly, effectively, short-,circuitingcapacitor I05, thelengthof eachpulse,canwbeacontrolled by the widthfof, the ,indicia 391. or the speedof the tape 31.

A wholly electronic reproducing system isillustrated inFig. 9. As before, theprogramming-iary, rangement of Fig. 4 is utilized,.the modification being in the portion of-thesystem-followin the wand b groups of terminals ,to ;99. ,Thera group less the ,zeroi terminal 89d, which, isnot used, ,is connected to the grid electrodesofw 5 (3011-, trol tubes I29,I3I, :I33,.--I35. ;and I31, while-the six 2) groups terminals are. connectedprespectively, to the grid electrodes ,of,.six additional control tubes I39, MI, I,43,tg l45, I 4:'I.andl -|49J-yfl The cathode electrodes of the ll controltubes' are connected to ground through 11 resistorsISI, to [15, respectively, each having a different valueas will appear subsequently-The plate BIQCr-I trodes of all tubes are connected together. Platepotential is applied through awload resistor I13, from terminal H5. The plates are also connected to one verticaldeflecting plate I15 ofra cathode ray tube I11. and coupled through an amplifier I19 to, a triggercircuit I8l, thel output of which is connected to one horizontaldeflecting plate I83 of the cathode ray tube I'll. TheF-I'B-r maining deflecting plates. are connectedrto ,potentiometers I85, ,I 81 which are used 1 tocenter; the electronbeam. H The cathode ray tube .I'l'I includes atspecial target electrode I89 provided with 35,distinctive masks I9I1 to I9I35 extendinglaterallyacrossthe target, as shown in greater detailoinFig. -w10. Each mask is shaped in a .predeterminedmanner so that as the electron beam sweeps horizontally along the maskthe targetfis shielded from the beam, to a greater orless extent. The variations of the shield arerecorded representationepfthe 35 basic sounds and may, for,example,,comprise sections of variable area sound film. Th ESBIQ-J cordings may be printed directly on thetarget by known photographic methods. ,Thettarget may ,be of secondary electron emissivemateriala In any event, the potential of the target varies in accordance with the variation in, the number of electrons striking it. The oscillatory, sound,- representing potential of the target is applied, to the, grid of an amplifier,l93 and reproduced by,

a loudspeaker, headset,,I9,5,:,v1or the, like; A l

though, the size of, the, drawingdoes notpermit illustrationof; the 35, different masks, itlwill; be understood that these may readily :be proyidedi :1 -i lt ae lsetiqal Qtltteiees estsm esi Jansen-t plished by deflecting the beam vertically. This is the function of the controltubes I29 to I49. Remembering that only one tube of a group and one tube of b group will be operative at a given time 'let us assume that positive potentials are appliedto terminals 9Ia and 89b to make tubes I29 and I39 conductive. Cathode resistors II and ISI are then adjusted to values which cause the common plate potential, which is applied to deflecting plate I15, to have the value necessary to deflect the beam upwardly to the first line l9l1. For the combination of tubes I 3| and I39, the value of cathode resistor IE3 is made somewhat lower so that more current flows through output resistor I13 and the deflection voltage is that requiredto drop the beam onto the second line I9I2. Similarly, for the other three control tubes of group a considered with the same tube I39 of group b the cathode resistors I55, I51 and I59 being adjusted to deflect the beam to the third, fourth and fifth lines, respectively. Considering the a group tubes with the second 15 group tube I4I, the cathode resistor I69 of the latter tube is adjusted to focus the beam on the sixth line I 9ls in conjunction with the first tube I29 of a group. Successive a group tubes thus each lower the beam one more line, as before, until line l9l10 is reached. The remaining control tubes of group b are adjusted similarly, each b group tube producing a change of 5 lines more than the preceding one, and each a group tube producing a change of one line more than the preceding one. There will therefore be a total of- 35 distinct vertical positions of the beam corresponding to and coinciding with the 35 sound tracks of the target from I9I1 to I9I35.

Finally, it is necessary to provide means for scanning each linefrom left to right, for example, once just after the vertical line selection has been accomplished. This function is accomplished by the amplifier I19 and the trigger circuit I81. Theamplifier is coupled to the combined plate circuit of the control tubes by a capac itor which applies a pulse to the amplifier as the vertical deflecting voltages are successively applied to the cathode ray tube I11. This pulse is amplified to the extent necessary to produce a short output pulse of the amplitude required to saturate the trigger tube for the smallest inputvoltage. The trigger circuit ISI is shown in detail in Fig. 11, and comprises a discharge tube I91 having its grid coupled to the output of amplifier I19 by a capacitor I99, The plate circuit includes a shunt capacitor 20I which is charged by a battery 203 through a resistor 205. Output is taken across'the capacitor. The change in the voltage applied to the vertical defleeting plate to adjust the beam to the desired vertical position causes a short pulse of positive potential to be applied to the grid of trigger tube I91. The tube is normally biased to cut off by bias battery 201, or the equivalent. Assuming that the capacitor Zlll has had time to become fully charged, a positive voltage equal to the battery 203 voltage is normally applied to horizontal deflecting plate I83 and the beam rests at or beyond the left hand edge of the target. The pulse suddenly saturates tube I91, discharging capacitor 20I and causing the beam to move to the right hand edge of the target at a very high rate. The-tube then goes to cut-oil, the capacitor begins to charge at a relatively slow rate, while the beam moves relatively slowly back-to its starting position. In the meanwhile the beam'has found its vertical position, so that it sweeps along or scans the desired sound track and produces a modulated output signal corresponding to the desired sound component of speech. The time constant of the trigger circuit is determined by resistor 205 and capacitor 20I. These are selected to produce a scanning rate which produces the desired sound. Of course the scanning rate is less than the interval between successive control signals from the programming circuit so that the selected line is scanned completely before the next pulse arrives. Alternatively, tube I91 may be a gas-discharge type tube. The drop in plate voltage due to the large current through the resistor 205 is eifective to extinguish the tube and permit the grid to regain control.

It will therefore be seen that the electronic generator produces under the control of the programming device a succession of audio sound components whose time sequence is determined by the coded indicia of tape 39 so as to produce by their successive combination the desired audible sounds.

In order to provide more accurate control of the vertical displacement of the beam so that the device will be free from small variations in the amplitude of the applied potentials which otherwise might deflect the beam to position intermediate two line traces, the device illustrated in Figs. 12 and 13 may be employed. As in the preceding cases. the programming device of Fig. 4 is utilized in its entirety so that combinatorial arrangements of the two series of voltages available at the 12 terminals 89a to 99a and 89b to 99?) may be employed. These voltages are utilized to control the vertical selection of the 35 positions of the target, in accordance with the principle employed in the Selectron fully described and claimed in a copending application of J. A. Rajchman, application Serial No. 665,031,

vfiled April 26, 1946 now Patent No. 2,494,670,

granted January 1'1, 1950.,

Referring particularly to Fig. 13, 35 horizontal grid wires 2051 to 20535 inclusive are arranged in front of the target electrode I89. The 35 grid wires are connected to 35 conductors of a resistance matrix 201. Orthogonal components of the resistance matrix comprises two groups of 6 con-- 1 V ductors each. The 6 conductors of the a group are connected, respectively, to the movable contacts arm of 6 single pole double throw switches 269, 2, 2I3, 2I5, 2I1 and 2I9 while the 6 conductors of the h group are similarly connected to the movable element of 6 additional single pole double throw switches bearing the same reference numerals but identified by a subscript 2). One contact terminal of each of the 12 switches is connected to a suitable source of negative potential available on conductor 2II while the remaining contact of each of the 12 switches is connected to a source of positive potential available on conductor 223. The switches are normally biased in one position and are moved to the other position by 12 actuating coils which are connected, respectively, to the 12 output terminals of Fig. 4, 89 to 99 and to ground through a common resistor 225,

As described in the copending application of Rajchman referred to above, electrons directed toward the target are permitted to pass through the gate between the grid wire and reach the target only when two adjacent wires are biased to an opening potential which may be cathode potential or a positive potential, depending on the type. Electrons will be turned back and prevented from passing between two negatively biased grid wires, or between one having an opening bias and an adjacent wire having a negative bias. It is to be understood that in accordance with the Rajchman application, the grid wire construction may embody either the potential barrier or the deflection type of oper-- ation. In the former case, each grid wire 295 will be in register with a positively biased accelcrating grid wire positioned between it and the source of electrons. In the latter case, the grid wires will have suflicient width in the direction of the electron beam axis so that the electrons will be controlled in accordance with the established theory of operation. In order not to confuse the drawings, these accelerating grid wires, or the equivalent construction, have not been shown.

In response to the operation of the programming circuits, described above, one switch of each group will be operated to connect, through the resistance matrix, two adjacent grid wires to the relatively positive conductor 223 for each unique combination of the 35 possible combinations. Thus for each combination one and only one gate will be opened between adjacent grid wires, thus assuring accurate and positive control of the electrons so that they will impinge on the desired recorded area of the target.

Fig. 12 shows a cathode ray tube 221 embodying a target IE9 and control grid operating on the Selectron principle. The control grid is not shown in detail in Fig. 12, but is indicated merely bya plurality of horizontal grid wires 205, it being understood that the complete operating circuit will be as described above in connection with Fig. 13. The tube includes a conventional beam forming device indicated by a cylinder 229 and also includes l conventional deflecting electrodes for controlling the vertical and horizontal movement of the beam. Since the actual vertical selection is accomplished by the selecting grid 205 it is, in the present case, only necessary to deflect the beam vertically at a continuously high rate, the rate preferably being substantially higher than any recorded frequency. This is accomplished, for. example, by connectin the output of a 10 k. 0. generator 23| between ground and the vertical deflecting plate I15, the complementary vertical deflecting plate being connected to a potentiometer I81 as before. Horizontal deflection across the selected recorded area of the target is accomplished by means of an amplifier i153 and trigger circuit Iill as in the modification illustrated in Fig. 9. Since this device is to cause the beam to move once in a horizontal direction from rightto left across the target, each time one of the 35 scanning areas has been selected, the control pulse for the trigger circuit may be derived from terminal 233 (Fig. 13) which is connected to the ungrounded terminal of resistor 225 in series with the actuating coils of the relays which control the potential of the horizontal grid elements. Thus, each time the indicia of the tape 31 move into the field of the illuminated area 33, two of the control relays (one in each group) are operated to select the required line to be scanned, and a pulse is generated across resistor 225 which is amplified and applied to the trigger circuit ml to cause the electron beam to scan the selected recorded area once and return to its initial starting point ready for the next excursion. As before, output is derived from target 189 by an amplifier I93 and successive 10 sound components representing intelligible speech are available at the output device I95.

What I claim is:

1. In a device of the character described, a plurality of tone generators for producing respectively distinctive audio frequency oscillatory vibrations, and control means for causing said generators to become successively operative in a predetermined time sequence, said control means comprising relatively movable control and responsive elements, said control element having recorded thereon two separate series of coded indicia and said responsive element being separately responsive to each series, said responsive element being connected to initiate operation of each said generator only in response to a unique combination of one indicia of each of said series.

2. A device of the character described in claim 1 in which each series of indicia comprises. n dis tinctive indicia to provide approximately n' unique indicia combinations for controlling approximately n generators.

3. A device of the character described in claim 1 in which said distinctive oscillatory vibrations are representative of the basic sound components of normal speech.

4. In a device of the character described, a

plurality of tone generators for producing, respectively, distinctive audio frequency soundrepresenting electrical oscillations, a utilization device, switching means for each generator for applying said oscillations individually to said utilization device, a control element havin recorded thereon two separate series of coded indicia, means separately responsive to each of said series for producing a separate control voltage corresponding to each indicium, and means for actuating each of said switching means by a unique combination of a control voltage corresponding to an indicium of each series of indicia.

.5. A device of the character described in claim 4 in which n distinctive indicia in each series controls approximately 11. separate switching means and thus 11 generators. Y

6. A device of the character described in claim 4 in which said means for actuating each of said switching means includes a resistance matrix.

'7. A device of the character described which includes a plurality of electrical signal supply circuits, a signal utilization device and switching means for each electrical supply circuit for connecting said circuits individually to said device, a control element having recorded thereon two separate series of coded indicia, means separately responsive to each of said series for producing a separate control voltage corresponding to each indicium, said control element and said responsive means being relatively movable, and means for actuating each of said switching means by. a unique combination of a control voltage corresponding to an indicium of each series, whereby said circuits are connected individually to said device in a time sequence determined by said coded indicia.

8. In a device of the character described, a plurality of tone generators for producing respectively distinctive audio frequency electrical oscillations, a utilization device, switching means operatively connected with each generator for applying said oscillations individually to said utilization device, a control element having recorded thereon two separate series of coded indicia, means separately responsive to each of said series for producing control voltages which vary in accordance with saidindicia, respectively, means for establishing relative movement between said control element and said responsive means, a pair of oscillators, means for varying the frequency of said oscillators in accordance with the variations of said control voltages, respec tively, means includinga plurality of band pass filters coupled to each of said oscillators for pro ducing a separate voltage corresponding to each indicium, and means for actuating each of said switching means by a unique combination of a voltage correspondingl to an indicium of each series of indicia, whereby said oscillations are applied to said device in a time sequence determined by said coded indicia.

9. A device of the character described in claim 41in which saidgenerators are constituted by a target of a material having a given secondaryelectron emissive characteristic having thereon distinctive regions ofa different secondary-electron emissive characteristic varying in area in predeterm ned patterns, and means for scanning said regions with an electronbeam, and wherein said switching means includes means for selec tively moving said beam from one to the other of said regions.

10. A device of the character described comprising a control element having recorded there on two separate series of coded indicia, means separately responsive to each of said series for producing. a separate control voltage correspondingto each indicium, said control element and said responsive means being relatively movable, a cathode ray tube having a target of a material having a given secondary-electron emissive char acteristic, means controlled by unique combinationsof said control voltages for causing said beam to impinge on given distinctive regions of said target, and to sweep once over the length of said region, means for causing the potential of said target to vary at distinctive audio frequencies as a function of the instantaneous position of said beam on said region, and output means coupled to said target andresponsive to said variations of potential.

11. A device of the character described in claim in which said means for causing the potential of said target to vary as a function Of the instantaneous position of said beam on said region comprises a shield positioned to intercept dif; ferent proportions of said beam at different positions of said beam, the resultant variation in each of said regions corresponding to a different component of speech.

12. A device of the character described comprising a control element having recorded thereon two separate complementary series of indicia comprising contrasting areas of different light transmission properties, photoelectric means as sociated with each series of indicia for producing output voltages varying in magnitude in accordance with each successive indicium, said control element and said photoelectric means being relatively movable, means controlled by each output. voltage for producing a. separate: control voltage corresponding to each indicium, a cathode ray tube having a cathode beam and a target, said target being subdivided'into a. plurality of regions extending laterally across said target, means controlled by unique combinations of-one control voltage corresponding to an indicium of each of said series for causing said beam to impinge on a given region of said target andto sweep once'over the length there0f, means associated with each of said regions for causing said beam to modulate distinctively the'potential of said target within an audio frequency range, and output means coupled to said target, whereby the successive distinctive audio frequency modulations of said target potential are produced in a predetermined time sequence determined by the pattern of said complementary indicia.

13. A system for artificially reproducing speech comprising tone generator means for individually reproducing the basic tones and sounds comprising the spoken language, means for selecting and combining the sound components in a controlled time sequence to reproduce artificially intelligible words comprising a programming de-. vice responsive to a predetermined limitednumber of coded indicia in two distinct series, means for deriving a controlling potential corresponding to each of said indicia, a plurality of control tubes corresponding in number to said series of basic tones for controlling said generator means, and a resistance control matrix coupling said control tubes to said control potential deriving means.

1 1. In a speech reproduction system, the combination of a plurality of tone generating means corresponding in number to the basic tones and sounds comprising a spoken language and being at least thirty-five in number, a control element having recorded thereon two separate series of coded indicia each less than six in number, means separately responsive to each of said series of indicia for producing a separate control voltage corresponding to each. indicium, and control means for each of said tone generating means responsive to a predetermined one Of a combination of said control voltages corresponding in number to the total of said tone generating means.

LESLIE E. FLORY.

REFERENCES CITED The following referencesare of record in the file of this patent:

UNITED STATES PATENTS Cox Nov. 10, 1942 

